Use Synth for exchange rates (#514)

* Switch currency seeding over to Synth

* Switch all exchange rates over to Synth

lib/tasks/currencies.rake

@@ -3,18 +3,18 @@ namespace :currencies do
   task seed: :environment do
     currencies = ENV["CURRENCIES"].split(",")
 
-    if currencies.count > 1 && ENV["OPEN_EXCHANGE_APP_ID"].present?
-      url = "https://openexchangerates.org/api/currencies.json"
+    if currencies.count > 1 && ENV["SYNTH_API_KEY"].present?
+      url = "https://api.synthfinance.com/currencies"
 
       response = Faraday.get(url) do |req|
-        req.params["app_id"] = ENV["OPEN_EXCHANGE_APP_ID"]
+        req.headers["Authorization"] = "Bearer #{ENV["SYNTH_API_KEY"]}"
       end
 
-      oxr_currencies = JSON.parse(response.body)
+      synth_currencies = JSON.parse(response.body)
 
       currencies.each do |iso_code|
         Currency.find_or_create_by(iso_code: iso_code) do |c|
-          c.name = oxr_currencies[iso_code]
+          c.name = synth_currencies["data"].find { |currency| currency["iso_code"] == iso_code.downcase }["name"]
         end
       end
 

lib/tasks/exchange_rates.rake

@@ -1,81 +1,26 @@
 namespace :exchange_rates do
-  desc "Fetch exchange rates from openexchangerates.org"
+  desc "Fetch exchange rates from Synth API"
   task sync: :environment do
-    app_id = ENV["OPEN_EXCHANGE_APP_ID"]
-    MININUM_DATE_RANGE = 30.days
-    MAXIMUM_DATE_RANGE = 120.days
-
-    # First, check what plan the user is on at OXR
-    # If the user is on the Developer plan, we can only fetch exchange rates for the past 30 days and must use the historical endpoint
-    account_check = Faraday.get("https://openexchangerates.org/api/usage.json") do |req|
-      req.params["app_id"] = app_id
-    end
-    account_details = JSON.parse(account_check.body)
-    quota_limit = account_details["data"]["usage"]["requests_quota"]
-
-    if quota_limit <= 10000
-      # First loop through all Currency records and fetch exchange rates for each, but use the historical endpoint, which only allows fetching one day at a time. For each currency, set the base currency to the currency's iso_code and the symbols to all other currencies' iso_codes
-      Currency.all.each do |currency|
-        (Date.today - MININUM_DATE_RANGE).upto(Date.today) do |date|
-          response = Faraday.get("https://openexchangerates.org/api/historical/#{date}.json") do |req|
-            req.params["app_id"] = app_id
-            req.params["base"] = currency.iso_code
-            req.params["symbols"] = Currency.where.not(iso_code: currency.iso_code).pluck(:iso_code).join(",")
-          end
-
-          if response.success?
-            rates = JSON.parse(response.body)["rates"]
-
-            rates.each do |currency_iso_code, value|
-              ExchangeRate.find_or_create_by(date: date, base_currency: currency.iso_code, converted_currency: currency_iso_code) do |exchange_rate|
-                exchange_rate.rate = value
-              end
-              puts "#{currency.iso_code} to #{currency_iso_code} on #{date}: #{value}"
-            end
-          else
-            puts "Failed to fetch exchange rates for #{currency.iso_code} on #{date}: #{response.status}"
-          end
+    Currency.all.each do |currency|
+      (Date.today - 30.days).upto(Date.today) do |date|
+        response = Faraday.get("https://api.synthfinance.com/rates/historical") do |req|
+          req.headers["Authorization"] = "Bearer #{ENV["SYNTH_API_KEY"]}"
+          req.params["date"] = date.to_s
+          req.params["from"] = currency.iso_code
+          req.params["to"] = Currency.where.not(iso_code: currency.iso_code).pluck(:iso_code).join(",")
         end
-      end
-    else
-      # Use Faraday to make a request openexchangerates.org time series endpoint
-      # Use the response to create or update exchange rates in the database
-      url = "https://openexchangerates.org/api/time-series.json"
-      start_date = (Date.today - MAXIMUM_DATE_RANGE).to_s
-      end_date = Date.today.to_s
 
-      # Loop through all Currency records and fetch exchange rates for each
-      Currency.all.each do |currency|
-        start_period = Date.parse(start_date)
-        end_period = Date.parse(end_date)
+        if response.success?
+          rates = JSON.parse(response.body)["data"]["rates"]
 
-        while start_period < end_period
-          current_end_date = [ start_period + 30.days, end_period ].min
-
-          response = Faraday.get(url) do |req|
-            req.params["app_id"] = app_id
-            req.params["start"] = start_period.to_s
-            req.params["end"] = current_end_date.to_s
-            req.params["base"] = currency.iso_code
-            req.params["symbols"] = Currency.where.not(iso_code: currency.iso_code).pluck(:iso_code).join(",")
-          end
-
-          if response.success?
-            rates = JSON.parse(response.body)["rates"]
-
-            rates.each do |date, rate|
-              rate.each do |currency_iso_code, value|
-                ExchangeRate.find_or_create_by(date: date, base_currency: currency.iso_code, converted_currency: currency_iso_code) do |exchange_rate|
-                  exchange_rate.rate = value
-                end
-                puts "#{currency.iso_code} to #{currency_iso_code} on #{date}: #{value}"
-              end
+          rates.each do |currency_iso_code, value|
+            ExchangeRate.find_or_create_by(date: date, base_currency: currency.iso_code, converted_currency: currency_iso_code) do |exchange_rate|
+              exchange_rate.rate = value
             end
-          else
-            puts "Failed to fetch exchange rates for period #{start_period} to #{current_end_date}: #{response.status}"
+            puts "#{currency.iso_code} to #{currency_iso_code} on #{date}: #{value}"
           end
-
-          start_period = current_end_date + 1.day
+        else
+          puts "Failed to fetch exchange rates for #{currency.iso_code} on #{date}: #{response.status}"
         end
       end
     end